Researchers in the United States have successfully teleported a quantum state of light through over 30 kilometers (approximately 18 miles) of fiber optic cable, achieving a remarkable breakthrough in quantum communication. This experiment, conducted in 2024, was carried out amidst substantial internet traffic, demonstrating a previously thought impossible engineering feat.
The work, led by Prem Kumar, a computing engineer at Northwestern University, marks a significant advancement toward establishing a quantum-connected computing network. While it may not revolutionize daily internet use, this ability to teleport quantum states using existing infrastructure could pave the way for enhanced encryption methods and new sensing technologies. Kumar expressed enthusiasm about the implications of their research, stating, “This is incredibly exciting because nobody thought it was possible.”
The teleportation process bears a resemblance to the fictional systems depicted in Star Trek, where objects are instantaneously transported across distances. In reality, quantum teleportation involves destroying a quantum state in one location and recreating it in another. This method requires the transmission of a single wave of information between the two points, a process that can easily be disrupted by external factors.
Quantum states are fragile, existing as a blend of possibilities that can quickly collapse into a definitive state when subjected to environmental disturbances. The challenge lies in preserving these states while transmitting them over busy optical fibers, which are typically filled with data, from bank transactions to streaming videos. The research team employed various techniques to channel the photons effectively, minimizing scattering and interference from the surrounding noise of internet traffic.
“We carefully studied how light is scattered and placed our photons at a judicial point where that scattering mechanism is minimized,” Kumar explained. “We found we could perform quantum communication without interference from the classical channels that are simultaneously present.”
While previous studies had successfully simulated the transmission of quantum information alongside classical data, Kumar’s team’s achievement is the first instance of actual quantum state teleportation occurring alongside real-world internet usage. This milestone suggests that a fully operational quantum internet may soon be realized, offering new capabilities in measurement, monitoring, and encryption without necessitating a complete overhaul of existing infrastructure.
“Quantum teleportation has the ability to provide quantum connectivity securely between geographically distant nodes,” Kumar noted. “Many people have long assumed that nobody would build specialized infrastructure to send particles of light. If we choose the wavelengths properly, we won’t have to build new infrastructure. Classical communications and quantum communications can coexist.”
This groundbreaking research has been published in the journal Optica, contributing to the growing body of knowledge in the field of quantum technologies. As the scientific community continues to explore these possibilities, the future of quantum communication looks promising, with the potential to transform how we connect and share information on a global scale.
